Phosphopantothenate—cysteine ligase

phosphopantothenate-cysteine ligase
Identifiers
EC number	6.3.2.5
CAS number	9023-50-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a phosphopantothenate-cysteine ligase also known as phosphopantothenoylcysteine synthetase (PPCS) is an enzyme that catalyzes the chemical reaction which constitutes the second of five steps involved in the conversion of pantothenate to Coenzyme A. The reaction is:

NTP + (R)-4'-phosphopantothenate + L-cysteine <math>\rightleftharpoons</math> NMP + diphosphate + N-[(R)-4'-phosphopantothenoyl]-L-cysteine

The nucleoside triphosphate (NTP) involved in the reaction varies from species to species. Phosphopantothenate—cysteine ligase from the bacterium Escherichia coli uses cytidine triphosphate (CTP) as an energy donor, whilst the human isoform uses adenosine triphosphate (ATP).

Nomenclature

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is (R)-4'-phosphopantothenate:L-cysteine ligase. This enzyme is also called phosphopantothenoylcysteine synthetase.

Gene

VALUE_ERROR (nil)
Identifiers
Aliases
External IDs	GeneCards: [1]
Orthologs
Species	Human	Mouse
Entrez	n/a	n/a
Ensembl	n/a	n/a
UniProt	n/a	n/a
RefSeq (mRNA)	n/a	n/a
RefSeq (protein)	n/a	n/a
Location (UCSC)	n/a	n/a
PubMed search	n/a	n/a
Wikidata
View/Edit Human

Phosphopantothenoylcysteine synthetase in humans is encoded by the PPCS gene.

Protein structure

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 1P9O, 1U7U, 1U7W, 1U7Z, and 1U80.

Further reading

• Brown GM (1959). "The metabolism of pantothenic acid". J. Biol. Chem. 234 (2): 370&ndash, 8. PMID 13630913.
• Strauss E, Kinsland C, Ge Y, McLafferty FW, Begley TP (2001). "Phosphopantothenoylcysteine synthetase from Escherichia coli Identification and characterization of the last unidentified coenzyme A biosynthetic enzyme in bacteria". J. Biol. Chem. 276 (17): 13513&ndash, 6. doi:10.1074/jbc.C100033200. PMID 11278255.
• Kupke T (2002). "Molecular characterization of the 4'-phosphopantothenoylcysteine synthetase domain of bacterial dfp flavoproteins". J. Biol. Chem. 277 (39): 36137&ndash, 45. doi:10.1074/jbc.M206188200. PMID 12140293.